Collecting data among participants belonging to a group, community or organization is a crucial step in social research. However, generally speaking, in the social sciences, the issue of access to the research field has not been widely or systematically studied and remains under-theorized. The goal of this study is to draw the participants' perspective on the question of accepting research into their classrooms and participating in it, an object that has usually been overlooked in studies on research field access. This article presents the results of a qualitative, exploratory study aimed at documenting teachers' representations relating to whether or not they wish to participate in research projects, when requested to do so by researchers. The analysis brought out a system comprising five categories of representations relating to participation or non-participation in an educational research project. These representations are related to (1) the teacher's daily tasks; (2) the teacher's professional development; (3) the teacher's professional identity and professional ideal; (4) the institutional and collegial context; and (5) the teacher's responsibility toward students. We discuss these categories and their implications for further research.